Raider,
I dunno when the last guns kill was but it came close a few times in desert storm when the initial batch of aim-7s had an 80%+ failure rate at launch. The last 2 USAF kills were in or rapidly approaching the visual arena due to missile failure and the rules of engagement may not always allow for BVR shots, resulting in a knife-fight. The Israelis may have a few modern jet guns kills but I'm not sure. I know for a fact that there were guns-only engagements in relatively recent South American conflicts.
Remember, it was only 3 years ago when F-15 pilots swore up and down that they would NEVER take their 55 million dollar fighter low enough to strafe, yet it's become an important option that all of our fighters bring to the table on the modern battlefield. We've had guys strafing within about 50 yards of troops in contact, and you can't do that with anything but a gun. You can't get that kind of accuracy with a podded gun, even if you have a suitable weapons station on which to hang it. It's gotten to the point that we made a serious effort to determine if we could teach F-15C pilots how to strafe. It didn't go too well for various reasons but it was important enough that we gave it a shot.
I don't know a single fighter jock who would honestly recommend getting rid of the internal gun, unless he/she has an agenda to push. There will likely be a tradeoff made with the JSF in certain variants due to airframe space limitations, but I know for a FACT that the service due to receive those fighters will regret that design deficiency. Every single time we've removed the internal gun from a US designed fighter, we've wished we had it back later on. Every single time.